1. Field of the Invention
The present invention relates to multicolor electrophotographic reproduction apparatus and methods and, more specifically, to the improved production of copy in selected colors.
2. Brief Description of the Prior Art
In U.S. Patent 4,045,218 an apparatus is described for producing color accented reproductions from originals of a single color. In this method, an original such as a letter is placed at a copier's exposure station and an indicator member adjusted to identify which lines are to be reproduced in which colors. For example, the first ten lines of an original black-on-white letter may be desired to be reproduced in say red and the remainder of the letter to be reproduced in its original color black. In this example the patent discloses that the entire original may be exposed onto a primary charged photoconductor to produce a latent electrostatic image thereof and the portion to be reproduced in black is erased by an electroluminescent panel. The remaining image is then developed with red toner. The original is then again exposed onto the photoconductor but this time the information to be reproduced in red is erased and the electrostatic latent image developed with black toner. The two toner images are then transferred to a copy sheet in registration with one another to provide the multicolored reproduction. The patent discloses that three colors may be provided in the reproductions where three developer stations are used.
A problem with the apparatus described in this patent is in the reproduction of originals with composite information. For example, it is often desirable to reproduce with its original coloration a multicolored pictorial while providing color accenting to line-type material such as alphanumerics and logos, etc. It would also be desirable to provide color accenting in many colors, for example 25, without providing significantly more color development units.